Lifting-jack.



No. 632,|97. Patented Aug. 29,1899.

' A. oLsEN.

LIFTING JACK.

(Application led Nov. 1, 1898.)

(No Model.)

. 17 Il", mi' l i 6 I I I d i l mi g il i mi@ ATTORNEY.

ANDRET OLSEN, OF NANAIMO, CANADA, ASSIGNOR OF ONE-HALF TO ALBERT E.FRASER, OF VANCOUVER, CANADA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 632,197, dated August29, 1899.

l Application filed November 1,1898. Serial No. 695,210. (No model.)

To all whom t may concern:

Be it known that I, ANDREW OLsEN, a citizen of the Dominion of Canada,residing at Nanaimo,in the Province of British Columbia, Canada, haveinvented a new and useful Lifting-Jack, of which the following is aspecification.

My invention relates to improvements in lifting-jacks of that class inwhich the lifting is done by a screw; and the object of my invention isto provide means for operating the same by a very slight movement of thelever having pawls thereon which engage in a rack or pawl-recessesarranged around the upper outer side of a fixed ring or fiange near theupper end of the lifting-screw.

I attain the above object by the mechanism illustrated intheaccompanying drawings, in which- Figure l shows an elevation or myliftingjack; and Fig. 2 shows a plan of the same, sectioned on line a a.

Similar letters and numerals referto similar parts throughout bothviews.

The top A of the frame of my jack is rigidly tied to the base-plate B bythe pillars C. Threaded into the top piece A and passing downwardtherethrough is a stout screw D, and arranged near the top of this screwis a fixed iiange b, which is provided on its top or upper side withpawl-recesses c. These recesses are placed at regular intervals and havevertical edges on both their pawl-en gaging sides, so that a reversalmovement for u nwinding or lowering the screw may be eected, as will befully understood presently.

Lying on top of the flange b and made to rotate freely on the top shankof the screw is a lever socket E. Securely pivoted to the rounded end ofthis lever-socket are pawls d, these being secured by bolts or pins e.The said pawls are formed, as shown, so as to engage the rack close totheir bearing-supports, and, as shown in Fig. 1, they are reversible,having oppositely-deflected teeth or dogs, so that when they arereversed the oppositelyprojected teeth will engage in the opposite wallsof the recesses, and thus provide for the lowering of the screw, asbefore mentioned. Above the upper-surface of the lever-socket the shankof the screw D is slightly reduced in diameter, and arranged to turn onthis, but resting on its end, is a head-piece F, the top of which isslightly enlarged to present a greater area of surface to the loadbeinglifted, as is the casein other jacks of this class. To

prevent the head piece F from being detached from the shank of thescrew, an annular groove is cut in said shank, as f, and a pin or bolt gis inserted therein. This allows the head to turn freely, but preventsit from becoming detached.

By reason of the pawl flange or ring b having the pawl-recesses therein,and the pawls d pivoted to the socket E, which is worked by the lever h,it is shown that a slight movement of such lever will turn the screw,and therefore the jack can be advantageously operated where very littlespace is available for the movement of the lever, this being one of theessential features of my invention.

It will be noticedthat by forming the screwshank with a fixedratchet-flange b a smooth hub portion extending up centrally from theflange and terminating the hub portion in a shoulder or seat for themember F to rest on, providing the extremities of the said shank with aspindle member 2, adapted to fit the socket in the member F, and forminga spindle with an annular groove to receive the end of the adjustingscrew g a very compact, simple, and easily-manipulated arrangement ofparts is produced. Thus by simply loosening the screw g the pawl-head Eis readily detached without disorganizing any of the component parts.Again, it provides for a perfect and stable turn-plate for the rotaryhead E, as at no time will the member F bear frictionally against it, asthe said member F is supported on the shoulder of the hub portion of theshank.

I am aware that j ack-screws havin g a screwshank provided with a:fiXedly-held iiange carrying the ratchet portions has been provided,and I therefore make no claim to such construction; but

What I do claim, and desire to secure by Letters Patent, is-

A lifting jack; comprising a supportingframe having a threaded bearing;a screwshank operating in said bearing; an annular bearing -iiangefixedly connected with the IOO rest member F, having a socket to receivethe grooved spindle end of the screw-shank, and an adj ustin g-screwcarried by the member F, adapted to engage the groove in the spindle, 15all being arranged substantial] y as shown and described.

ANDREV OLSEN.

- Witnesses:

W. G. TRETHEWEY, ROWLAND BRITTAIN.

